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- CO oxidation (2)
- Ru (2)
- CO desoprtion (1)
- CO desorption (1)
- Coadsorbtion (1)
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- Density functional theory (1)
- Femtosecond (1)
- Gold nanoparticles (1)
- Layer-by-layer assembly (1)
- Light-responsive etalons (1)
- Optical lasers (1)
- Oxygen (1)
- Photothermal effect (1)
- Poly(N-isopropylacrylamide) microgels (1)
- Potential of mean force (1)
- Pump-probe (1)
- Responsive polymers (1)
- Ru(0001) (1)
- THz pulses (1)
- Two-temperature model (1)
- Valence electron structure (1)
- X-ray laser pulses (1)
- X-ray spectroscopy (1)
Articles 1 - 5 of 5
Full-Text Articles in Other Chemistry
Photothermally Induced Optical Property Changes Of Poly (N-Isopropylacrylamide) Microgel-Based Etalons, Molla R. Islam, Jessica Irvine, Michael J. Serpe
Photothermally Induced Optical Property Changes Of Poly (N-Isopropylacrylamide) Microgel-Based Etalons, Molla R. Islam, Jessica Irvine, Michael J. Serpe
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Poly(N-isopropylacrylamide) microgel-based optical devices were designed such that they can be stimulated to change their optical properties in response to light produced by a light-emitting diode (LED). The devices were fabricated by sandwiching the synthesized microgels between two Cr/Au layers all supported on a glass coverslip with gold nanoparticles (AuNPs) deposited. Here, we found that these devices can be stimulated to change their optical properties when exposed to green LED light, which excites the AuNPs and increases the local temperature, causing the thermoresponsive microgels to decrease in diameter, resulting in a change in the devices’ optical properties. We also found …
Thz-Pulse-Induced Selective Catalytic Co Oxidation On Ru, Jerry L. Larue, Tetsuo Katayama, Aaron Lindenberg, Alan S. Fisher, Henrik Öström, Anders Nilsson, Hirohito Ogasawara
Thz-Pulse-Induced Selective Catalytic Co Oxidation On Ru, Jerry L. Larue, Tetsuo Katayama, Aaron Lindenberg, Alan S. Fisher, Henrik Öström, Anders Nilsson, Hirohito Ogasawara
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We demonstrate the use of intense, quasi-half-cycle THz pulses, with an associated electric field component comparable to intramolecular electric fields, to direct the reaction coordinate of a chemical reaction by stimulating the nuclear motions of the reactants. Using a strong electric field from a THz pulse generated via coherent transition radiation from an ultrashort electron bunch, we present evidence that CO oxidation on Ru(0001) is selectively induced, while not promoting the thermally induced CO desorption process. The reaction is initiated by the motion of the O atoms on the surface driven by the electric field component of the THz pulse, …
Strong Influence Of Coadsorbate Interaction On Co Desorption Dynamics On Ru(0001) Probed By Ultrafast X-Ray Spectroscopy And Ab Initio Simulations, H. Xin, Jerry L. Larue, H. Öberg, M. Beye, M. Dell'angela, J. J. Turner, J. Gladh, M. L. Ng, J. A. Sellberg, S. Kaya, G. Mercurio, F. Hieke, D. Nordlund, W. F. Schlotter, G. L. Dakovski, M. P. Minitti, A. Föhlisch, M. Wolf, W. Wurth, H. Ogasawara, J. K. Nørskov, H. Öström, L. G. M. Pettersson, A. Nilsson, F. Abild-Pedersen
Strong Influence Of Coadsorbate Interaction On Co Desorption Dynamics On Ru(0001) Probed By Ultrafast X-Ray Spectroscopy And Ab Initio Simulations, H. Xin, Jerry L. Larue, H. Öberg, M. Beye, M. Dell'angela, J. J. Turner, J. Gladh, M. L. Ng, J. A. Sellberg, S. Kaya, G. Mercurio, F. Hieke, D. Nordlund, W. F. Schlotter, G. L. Dakovski, M. P. Minitti, A. Föhlisch, M. Wolf, W. Wurth, H. Ogasawara, J. K. Nørskov, H. Öström, L. G. M. Pettersson, A. Nilsson, F. Abild-Pedersen
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We show that coadsorbed oxygen atoms have a dramatic influence on the CO desorption dynamics from Ru(0001). In contrast to the precursor-mediated desorption mechanism on Ru(0001), the presence of surface oxygen modifies the electronic structure of Ru atoms such that CO desorption occurs predominantly via the direct pathway. This phenomenon is directly observed in an ultrafast pump-probe experiment using a soft x-ray free-electron laser to monitor the dynamic evolution of the valence electronic structure of the surface species. This is supported with the potential of mean force along the CO desorption path obtained from density-functional theory calculations. Charge density distribution …
Optical Laser-Induced Co Desorption From Ru(0001) Monitored With A Free-Electron X-Ray Laser: Dft Prediction And X-Ray Confirmation Of A Precursor State, H. Öberg, J. Gladh, M. Dell'angela, T. Anniyev, M. Beye, R. Coffee, A. Föhlisch, T. Katayama, S. Kaya, Jerry L. Larue, A. Møgelhøj, D. Nordlund, H. Ogasawara, W. F. Schlotter, J. A. Sellberg, F. Sorgenfrei, J. J. Turner, M. Wolf, W. Wurth, H. Öström, A. Nilsson, J. K. Nørskov, L. G. M. Pettersson
Optical Laser-Induced Co Desorption From Ru(0001) Monitored With A Free-Electron X-Ray Laser: Dft Prediction And X-Ray Confirmation Of A Precursor State, H. Öberg, J. Gladh, M. Dell'angela, T. Anniyev, M. Beye, R. Coffee, A. Föhlisch, T. Katayama, S. Kaya, Jerry L. Larue, A. Møgelhøj, D. Nordlund, H. Ogasawara, W. F. Schlotter, J. A. Sellberg, F. Sorgenfrei, J. J. Turner, M. Wolf, W. Wurth, H. Öström, A. Nilsson, J. K. Nørskov, L. G. M. Pettersson
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We present density functional theory modeling of time-resolved optical pump/X-ray spectroscopic probe data of CO desorption from Ru(0001). The BEEF van der Waals functional predicts a weakly bound state as a precursor to desorption. The optical pump leads to a near-instantaneous (< 100 fs) increase of the electronic temperature to nearly 7000 K. The temperature evolution and energy transfer between electrons, substrate phonons and adsorbate is described by the two-temperature model and found to equilibrate on a timescale of a few picoseconds to an elevated local temperature of ~ 2000 K. Estimating the free energy based on the computed potential of mean force along the desorption path, we find an entropic barrier to desorption (and by time-reversal also to adsorption). This entropic barrier separates the chemisorbed and precursor states, and becomes significant at the elevated temperature of the experiment (~ 1.4 eV at 2000 K). Experimental pump-probe X-ray absorption/X-ray emission spectroscopy indicates population of a precursor state to desorption upon laser-excitation of the system (Dell'Angela et al., 2013). Computing spectra along the desorption path confirms the picture of a weakly bound transient state arising from ultrafast heating of the metal substrate.
Probing The Transition State Region In Catalytic Co Oxidation On Ru, H. Öström, H. Öberg, H. Xin, Jerry L. Larue, M. Beye, M. Dell'angela, J. Gladh, M. L. Ng, J. A. Sellberg, S. Kaya, G. Mercurio, D. Nordlund, M. Hantschmann, F. Hieke, D. Kühn, W. F. Schlotter, G. L. Dakovski, J. J. Turner, M. P. Minitti, A. Mitra, S. P. Moeller, A. Föhlisch, M. Wolf, W. Wurth, M. Persson, J. K. Nørskov, F. Abild-Pedersen, H. Ogasawara, L. G. M. Pettersson, A. Nilsson
Probing The Transition State Region In Catalytic Co Oxidation On Ru, H. Öström, H. Öberg, H. Xin, Jerry L. Larue, M. Beye, M. Dell'angela, J. Gladh, M. L. Ng, J. A. Sellberg, S. Kaya, G. Mercurio, D. Nordlund, M. Hantschmann, F. Hieke, D. Kühn, W. F. Schlotter, G. L. Dakovski, J. J. Turner, M. P. Minitti, A. Mitra, S. P. Moeller, A. Föhlisch, M. Wolf, W. Wurth, M. Persson, J. K. Nørskov, F. Abild-Pedersen, H. Ogasawara, L. G. M. Pettersson, A. Nilsson
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Femtosecond x-ray laser pulses are used to probe the CO oxidation reaction on Ru initiated by an optical laser pulse. On a timescale of a few hundred femtoseconds, the optical laser pulse excites motions of CO and O on the surface allowing the reactants to collide and, with a transient close to a picosecond (ps), new electronic states appear in the O K-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond-formation between CO and O with a distribution of OC—O bond lengths close to the transition state (TS). After …